Food Security and Nutritional Status of Women Shellfishers and The Potential Role of Oysters as a Source of Dietary Minerals and Heavy Metals in Three Estuarine Sites in Ghana

Abstract

Background: Food insecurity in Ghana has significantly worsened over the past decade, leading to rising hunger and malnutrition, particularly among women. Thus, the Food and Agricultural Organization recommends integrating local food systems into food and nutrition security efforts. In Ghana’s coastal communities, oysters are valuable food resource and could offer an affordable source of protein and essential micronutrients like iron and zinc and thereby improve women's food security and nutritional status (anaemia and overweight/obesity). However, pollution and ecosystem degradation threaten sustainable oyster production and could impact women’s food security, anaemia and overweight/obesity status in these communities. This study aimed to compare the household food insecurity, dietary intake, anaemia, and overweight/obesity among women of reproductive age engaged in oyster harvesting, processing, and retailing (hereafter, women shellfishers) at three selected estuarine sites in Ghana. Additionally, the study aimed to determine the factors associated with household food insecurity, anaemia and overweight/obesity status and assess the potential of oysters as a source of dietary minerals for women shellfishers at the three estuarine sites. Methods: This cross-sectional study was conducted at three estuarine sites: Bortianor Tsokomey-Tetegu area in the Greater Accra Region (Densu estuary), New Amanful-Apremdo Beahu area in the Western Region (Whin estuary), and Ekumfi Narkwa in the Central Region (Narkwa Lagoon). A total of 504 women shellfishers were recruited across the three selected sites. Data on household characteristics, food insecurity, and dietary intake were collected using a structured questionnaire and repeated 24-hour dietary recalls. Overweight/obesity (≥25 kg/m2), and anaemia (<12 g/dl) status were assessed through anthropometric measurements and capillary blood samples. Additionally, 915 oyster samples from the three selected sites were analysed for mineral composition using atomic absorption spectrometry. Descriptive statistics were used to summarise participants’ characteristics and the mineral consents of the oysters. Chi-Square test was used to compare the rates of anaemia, overweight/obesity, household food insecurity, and nutrient inadequacies (iron, zinc, calcium, magnesium, potassium, and phosphorus) across the sites, while multiple logistic regression models were used to determine the factors associated with anaemia, overweight/obesity, and household food insecurity in separate models at a statistical significance of 0.05. The mean mineral contents of oysters were compared across the three sites using ANOVA. Health risks related to oyster consumption of the women shellfishers were evaluated using the Hazard Index (HI) and Cancer Index (CI). Ethics approval was obtained from the Ghana Health Service (GHS-ERC 015/12/20). Results: The mean ± SD age of the women shellfishers was 31.6 ± 9.1 years. The women had a mean ± SD of 4.9 ± 4 years of schooling, with 44.8% identified as literate. A slight majority were married (61.3%). The average household size was 6, and the household poverty probability index for the study population was 13%. Household food insecurity prevalence was high across all sites, recorded at 93.5% at the Densu estuarine site, 93.1% at the Narkwa Lagoon site, and 88.5% at the Whin estuarine site, with no statistically significant differences observed between sites (p = 0.218). In contrast, the prevalence of overweight/obesity varied significantly across sites, with rates of 58.3% at Densu, 43.1% at Whin, and 27.6% at Narkwa Lagoon (p < 0.001). Anaemia prevalence also differed significantly across sites, with 25% at Densu, 20% at Narkwa Lagoon, and 15% at Whin (p = 0.025). Residing in the Densu site, compared to the Whin site, was significantly associated with increased odd of household food insecurity (aOR=3.14, CI: 1.18-8.33; p=0.022). However, a unit increased in household assets was significantly associated with reduced odd of household food insecurity (aOR=0.73, CI: 0.54-0.98; p=0.037). The odds of overweight/obesity were 70% lower in women under 25 years compared to those aged 45 years and older (aOR=0.30, CI: 0.11–0.85; p=0.006). Married women had nearly twice the odds of being overweight/obese compared to those who were never married (aOR=1.93, CI: 1.07–3.30; p=0.027). An increase in household poverty rate was associated with reduced odds of overweight/obesity (aOR=0.97, CI: 0.95–0.99; p=0.011). Women in the middle tertile of nutrient-rich dietary patterns had nearly double the odds of being overweight/obese compared to those in the lower tertile (aOR=1.68, CI: 1.01–2.78; p=0.046). The odds of anaemia were lower in overweight (aOR=0.56, CI: 0.32–0.98; p=0.041) and obese (aOR=0.27, CI: 0.12–0.61; p=0.002) women compared to those with normal weight. Residing in the Densu site, compared to the Whin site, was significantly associated with twice the odds of anaemia (aOR=2.24, CI: 1.20–4.18; p=0.012). However, no significant association was found between oyster intake and the odds of anaemia (aOR=1.58, CI: 0.83–3.02; p=0.168). The women’s average caloric intake differed significantly across sites, with values of 1377 kcal at Densu, 1470 kcal at Whin, and 1592 kcal at Narkwa Lagoon (p=0.011). Iron intake was similar across sites, with averages of 9.4 mg at Densu, 9.1 mg at Narkwa Lagoon, and 9.4 mg at Whin (p=0.858). Average zinc intake also showed no significant variation, recorded at 6.4 mg for Densu, 5.6 mg for Narkwa Lagoon, and 5.9 mg for Whin (p=0.121). Oyster consumption contributed 17.2% (1.6 mg/day) of the average daily iron intake and 18.3% (1.1 mg/day) of the average daily zinc intake. The prevalence of nutrient inadequacy, assessed across six nutrients, showed no significant variation among sites, with rates of 91.5% at Densu, 90.0% at Whin, and 94.8% at Narkwa Lagoon (p=0.240). The mean mineral concentrations (mg/kg wet weight) in the oysters were potassium (4282), phosphorus (3470), calcium (2698), and magnesium (937), iron (120.5), zinc (82.4), chromium (22.1), copper (8.5), manganese (7.2), and selenium (5.4). Heavy metal concentrations were arsenic (0.102), mercury (0.038), cadmium (0.037), and lead (0.032). The Hazard Index (HI) ranged from 0.0004 to 1.81 (mean 0.071), indicating low health risks. The Cancer Index (CI) for arsenic, cadmium, and lead ranged from 1.3 x 10⁻⁶ to 5.8 x 10⁻⁴, suggesting minimal cancer risk. Selenium provided notable nutritional benefits, with a health benefit value ranging from 0.05 to 94.44 (mean 5.38). Conclusion: The study found high prevalence of household food insecurity and overweight/obesity among women shellfishers, along with inadequate intake of key micronutrients like iron and zinc. Oysters were found to be valuable sources of dietary minerals. These findings highlight the need for targeted interventions to improve access to nutritious foods, raise awareness of dietary needs, and address both food insecurity and obesity. The study recommends that nutrition education and obesity prevention be integrated into reproductive health services to tackle the dual burden of malnutrition and improve well-being.